Amphoteric graft copolymers of xanthomonas hydrophilic colloid and partially N-aminomethylated acrylamide

ABSTRACT

A series of novel amphoteric graft copolymers of xanthomonas hydrophilic colloid and partially N-aminoalkylated acrylamide has been prepared by reacting the corresponding acrylamide copolymer with an alkyl amine and an active aldehyde. The new copolymer is cationized via acidification or quaternization, and is reverted to its anionic form via basification.

BACKGROUND OF THE INVENTION

This invention relates to graft copolymers of xanthomonas hydrophiliccolloid and partially N-aminoalkylated acrylamide. The xanthomonascolloid is an anionic heteropolysaccharide containing mannose, glucose,and glucuronic acid groups. The copolymerization of the anionic polymerwith acrylamide is known and its method of preparation is described inthe U.S. Pat. No. 3,708,446. However, these copolymers are quite stablein aqueous media to changes in pH ranging from 2 to 12 indicating thatthey are very weak ionic polymers. It is desirable to create anamphoteric polymer which can be used either as a cationic polymer or ananionic polymer.

To create the desired new and easily ionizable copolymers, the aminofunctions of the acrylamides present in the xanthomonascolloid-acrylamide copolymers are partially converted toaminoalkylamines via Mannich reaction. Although the method has beenapplied to polyacrylamide, it has not been used in modifying any of thexanthomonas-acrylamide copolymers which incorporate all the xanthomonasheteropolysaccharide functional groups such as hydroxyl, carboxyl, esterand ketal. Surprisingly, these active functional groups have notinterfered with the aminoalkylation.

Therefore it is an object of the present invention to generate newamphoteric graft copolymers of xanthomonas hydrophilic colloid andpartially N-aminoalkylated acrylamide which retain many of the desirablecharacteristics of the anionic heteropolysaccharide xanthomonas colloidwhile at the same time, having the desirable cationic characteristics ofthe N-aminoalkylated acrylamide.

An additional object of this invention is to provide a suitableaminoalkylation process under well-controlled conditions for thecreation of these novel copolymers.

DETAILED DESCRIPTION OF THE INVENTION

The novel amphoteric copolymers of this invention are graft copolymersof xanthomonas hydrophilic colloid and partially N-aminoalkylatedacrylamide in which the weight ratio of xanthomonas colloid to theacrylamide (ZN:AM) ranges between 1:1 to 1:10, and wherein in each ofthe new polymers, the percentage of the N-aminoalkylated acrylamide(NAM%) groups ranges from 30% to 85% of the total available acrylamidegroups.

The N-aminoalkylated acrylamide function is defined in formula 1,##STR1## which is cationized via acidification to form an acid additionsalt of formula 2, or quaternization to form the quaternary salt offormula 3, ##STR2## wherein R and R¹ are independently lower alkylespecially C₁₋₆ alkyl; R² is hydrogen, lower alkyl especially C₁₋₆alkyl, or benzyl; R³ is lower alkyl especially C₁₋₆ alkyl, or benzyl;and A.sup.⊖ is an anion of a strong acid such as hydrochloric acid,hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid,trichloroacetic acid, trifluoroacetic acid, P-tolnoylsulfonic acid,2,4-dinitrophenyl sulfonic acid, or the like.

First, with regard to the weight ratio of the xanthomonas colloid to theacrylamide (ZN:AM), the preferred form of the copolymers of thisinvention is that wherein the weight ratio ZN:AM is from 1:1 to 1:5especially from 1:1 to 1:3 for higher aqueous viscosity.

Second, concerning the percentage of the N-aminoalkylated acrylamide ofthe total available acrylamide groups (NAM%), the preferred form of thecopolymers of this invention is that wherein the percentage, NAM%,ranges from 45% to 55%.

Third, regarding the N-aminoalkylated acrylamide function, the preferredform of the copolymers of the present invention is that wherein R and R¹represent independently C₁₋₃ alkyl such as methyl, ethyl or propyl; R²represents hydrogen, methyl or benzyl; R³ represents C₁₋₄ alkyl such asmethyl, ethyl, propyl or butyl; and A.sup.⊖ is a halide anion such aschloride, bromide, or iodide.

A still more preferred version of this invention is that wherein R andR¹ are both methyl; R² is hydrogen; R³ is methyl; and A.sup.⊖ ischloride.

The aminoalkylation is carried out in an inert solvent such as water, alower alkanol such as methanol, ethanol, a di(lower alkyl)ketone such asacetone, methyl ethyl ketone or diethyl ketone, a lower alkyl loweralkanoate such as methyl or ethyl acetate or the like, or mixturesthereof. The process comprises the treatment of a suitable copolymerwith a dialkylamine of the formula ##STR3## wherein R and R¹ are aspreviously defined, at about 25° C. to about 100° C. preferably about65° C. to 75° C. for a sufficient length of time, usually 10-60 min.followed by subsequent treatment with an aldehyde of the formula R² CHO,wherein R² is as previously defined, at about 25° C. to about 100° C.,preferably 65° C. to 75° C. until the reaction is complete, usuallyabout 15 min. If desired, the resulting product is then cationized by(1) addition of a strong acid of formula HA wherein the anion thereof,A.sup.⊖, is as previously defined to form the acid addition salt offormula 2; or (2) quaternization with an appropriate reagent such as analkyl halide of the formula R³ A.sub.α is selected from chloride,bromide or iodide. Again if desired, the resulting quaternary halideform (2) is basified with a strong base such as sodium hydroxide,potassium hydroxide, ammonium hydroxide or the like, to form thecorresponding quaternary hydroxide of partial formula ##STR4## followedby salt formation with a strong acid HA to form the quaternary salt offormula 3.

Similarly upon basification with an inorganic base such as sodiumhydroxide, sodium bicarbonate, potassium carbonate, and ammoniumhydroxide, or the like, the ammonium salts of the new copolymers offormula 2, are reverted to their anionic forms containing theN-acrylamidoalkylamine function as shown in formula 1. While in themeantime the glucuronic acid molecules contained in the xanthomonascolloid are converted to carboxylate salts.

The new copolymers are used as retarding or leveling agents in dyeingtextiles such as acrylic fabrics. Usually a 0.5% to 1.5% solution of thecopolymer, based on the weight of the fabric to be dyed, containing0.25% to 1.0% of the dye, also based on the weight of the fabric to bedyed, in a polar solvent such as water, methanol, ethanol, acetone oraqueous solutions thereof is adjusted to a pH value required by the dyeused, with a weak acid such as acetic acid, propionic acid or the like.The fabric is then immersed in this solution and the entire mixture isheated to reflux until the dyeing process is completed, usually about 1hour to about 2 hours.

Other uses of the new copolymers include flocculants or pigmentretention aids in paper manufacturing or coagulant aids or agglomeratingagents in water treatment.

EXAMPLE 1

To a solution of 8.0 g of xanthomonas hydrophilic colloid-acrylamide(1:3) copolymer in 300 ml. of water at 70° C. is added 19.0 g. of 40%aqueous dimethylamine. The reaction solution is stirred for about 5minutes before 5.8 g. of paraformaldehyde is added slowly. After theaddition is completed, the reaction mixture is stirred for an additional20-40 minutes, and then cooled to 55° C. While stirring, 6.0 g. ofammonium chloride and 8.4 g. of concentrated hydrochloric acid are addedand the mixture is stirred for an additional 30 minutes before it iscooled to room temperature and diluted with 600 ml. of acetone toprecipitate the product. After filtration, it is dried in vacuo at 50°C. and then milled to 11.3 g. (65%) of a 40 mesh powder which wasinsoluble in water, showed ir bands at 3050 cm⁻¹ (NH₄ ⁺), 1670 cm⁻¹ and1550 cm⁻¹ ##STR5## Based on the % weight add-on (41.3%), it is estimatedthat 35.3% of the original acrylamide function has been aminomethylated.

EXAMPLE 2

In the similar manner as described in Example 1, 12.0 g. of xanthomonashydrophilic colloid-acrylamide (1:1) copolymer is treated with 19 g. of40% dimethylamine and 5.8 g. of paraformaldehyde to afford 15 g. (70.4%)of a new copolymer which is insoluble in water. Based on the % weightadd-on (25%), it is estimated that 32.3% of the original acrylamidefunction has been aminomethylated.

EXAMPLE 3

In the similar manner as described in Example 1, 7.2 g. of xanthomonashydrophilic colloid-acrylamide (1:5) copolymer is treated with 40%aqueous dimethylamine (19 g.) and paraformaldehyde (5.8 g.) to afford14.9 g. (89.9%) of a new, water soluble copolymer in which 82.8% of theexisting acrylamide is dimethylaminomethylated. The viscosity of a 1%aqueous solution of the product was 25 cps.

Employing the same procedures as described in Examples 1, 2 and/or 3,but substituting for the copolymers, aldehydes and amines used thereinsimilar stoichiometric amounts of the copolymers, aldehydes and aminesas defined below in Table I, a series of new aminoalkylated copolymersare prepared according to the previously described process as summarizedbelow in equations (1), (2) and (3): ##STR6##

A selected group of these new copolymers are described below in Table I:

                                      TABLE I                                     __________________________________________________________________________    New Copolymer(1)                                                              ZN:AM                       Acid Addition                                                                           Quaternary                              Weight                                                                             Weight %               Salt (2)  Salt (3)                                ratio                                                                              NAM % R     R.sup.1                                                                             R.sup.2                                                                            A.sup.⊖                                                                         R.sup.3                                                                             A.sup.⊖                   __________________________________________________________________________    1:1  30-40 C.sub.2 H.sub.5                                                                     N-C.sub.4 H.sub.9                                                                   CH.sub.3                                                                           Cl.sup.⊖                                                                        C.sub.2 H.sub.5                                                                     Cl.sup.⊖                  1:2  40-50 n-C.sub.3 H.sub.7                                                                   n-C.sub.3 H.sub.7                                                                   C.sub.2 H.sub.5                                                                    Br.sup.⊖                                                                        n-C.sub.3 H.sub.7                                                                   Br.sup.⊖                  1:3  50-60 i-C.sub.3 H.sub.7                                                                   n-C.sub.4 H.sub.9                                                                   n-C.sub.3 H.sub.7                                                                  I.sup.⊖                                                                         CH.sub.3                                                                            I.sup.⊖                   1:4  60-70 n-C.sub.4 H.sub.9                                                                   C.sub.6 H.sub.5 CH.sub.2                                                            n-C.sub.4 H.sub.9                                                                  CF.sub.3 COO.sup.⊖                                                              n-C.sub.4 H.sub.9                                                                   HSO.sup.⊖.sub.4           1:5  70-80 n-C.sub.5 H.sub.11                                                                  C.sub.2 H.sub.5                                                                     n-C.sub.5 H.sub.11                                                                 CCl.sub.3 COO.sup.⊖                                                             CH.sub.3                                                                            H.sub.2 PO.sup.⊖.sub.3                                                3                                 1:6  75-85 i-C.sub.5 H.sub. 11                                                                 cyclohexyl                                                                          n-C.sub.6 H.sub.13                                                                 HSO.sup.⊖.sub.4                                                                 i-C.sub.4 H.sub.9                                                                   CF.sub.3 COO.sup.⊖        1:7  75-85 n-C.sub.6 H.sub.13                                                                  CH.sub.3                                                                            H    H.sub.2 PO.sup.⊖.sub.4                                                          i-C.sub.5 H.sub.11                                                                  CCl.sub.3 COO.sup.⊖       1:8  75-85 cyclohexyl                                                                          cyclohexyl                                                                          H                                                                                   ##STR7## cyclohexyl                                                                           ##STR8##                         1:9  75-85 i-C.sub.4 H.sub.9                                                                   C.sub.6 H.sub.5 CH.sub.2                                                            C.sub.6 H.sub.5 CH.sub.2                                                            ##STR9## C.sub.6 H.sub.5 CH.sub.2                                                             ##STR10##                         1:10                                                                              75-85 CH.sub.3                                                                            t-C.sub.4 H.sub.9                                                                   C.sub.6 H.sub.5 CH.sub.2                                                           Cl.sup.⊖                                                                        C.sub.6 H.sub.5 CH.sub.                                                             Cl.sup.⊖                  __________________________________________________________________________

What is claimed is:
 1. Amphoteric graft copolymers of xanthomonashydrophilic colloid and partially N-aminoalkylated acrylamide whereinthe amidoalkylamino function has the formula: ##STR11## or the acidaddition salts thereof of the formula: ##STR12## or the quaternary saltsthereof of the formula: ##STR13## wherein R and R¹ are independentlylower alkyl; R² is hydrogen, lower alkyl, or benzyl; R³ is lower alkyl,or benzyl; and A.sup.⊖ is an anion of a strong acid, wherein the weightratio of xanthomonas hydrophilic colloid to the acrylamide (ZN:AM)ranges between 1:1 to 1:10, and wherein the percentage of theamidoalkylamine function based on the total available acrylamide groups(NAM%) ranges 30-85%.
 2. The acid addition salts of the copolymers ofclaim 1 wherein A.sup.⊖ is chloride, bromide or iodide.
 3. Thequaternary salts of the copolymers of claim 1 wherein R³ is C₁₋₄ alkyl,and A.sup.⊖ is chloride, bromide or iodide.
 4. The copolymers of claim 1wherein the ZN:AM ranges between 1:1 to 1:5.
 5. The copolymers of claim1 wherein the ZN:AM ranges between 1:1 to 1:3.
 6. The copolymers ofclaim 1 wherein the NAM% is 45% to 55%.
 7. The copolymers of claim 1wherein R and R¹ are independently C₁₋₃ alkyl and R² is hydrogen,methyl, or benzyl.
 8. The copolymers of claim 1 wherein R and R¹ areboth methyl and R² is hydrogen.
 9. The acid addition salts of thecopolymer of claim 8 wherein A.sup.⊖ is chloride, bromide or iodide. 10.The acid addition salt of the copolymers of claim 8 wherein A.sup.⊖ ischloride.
 11. The quaternary salt of the copolymers of claim 8 whereinR³ is C₁₋₄ alkyl, and A.sup.⊖ is chloride, bromide or iodide.
 12. Thequaternary salt of the copolymers of claim 8 wherein R³ is methyl,A.sup.⊖ is chloride.
 13. A process for preparation of grafted copolymersof xanthomonas hydrophilic colloid and partially N-aminoalkylatedacrylamide wherein the N-aminoalkylated acrylamide function has theformula: ##STR14## comprising reacting a xanthomonas hydrophiliccolloid-acrylamide graft copolymer wherein the weight ratio ofxanthomonas hydrophilic colloid to acrylamide (ZN:AM) ranges between 1:1to 1:10, with a dialkylamine of formula ##STR15## wherein R and R¹ areindependently lower alkyl, and an aldehyde of formula:

    R.sup.2 CHO

wherein R² is hydrogen or lower alkyl, in an inert solvent followed, ifdesired, by cationization with (1) an acid of formula HA to form an acidaddition salt of partial formula ##STR16## wherein A.sup.⊖ is an anionof a strong acid, or (2) with an alkyl halide of formula R³ A.sub.α toform a quaternary salt of partial formula ##STR17## wherein R³ is loweralkyl or benzyl, and A⁻.sub.α is chloride, bromide or iodide, followed,if desired, by basification with a strong base to form a quaternaryhydroxide of partial formula: ##STR18## followed by salt formation witha strong acid of formula HA to produce the quaternary salt of partialformula ##STR19##